1. Field of the Invention
The present invention deals with the field of spherical plain bearings generally and with means for sealing thereof for retaining lubrication between the generally spherical bearing surfaces and for preventing the movement of contaminants therebetween. Such spherical plain bearings normally include an inner and outer race member wherein the inner race member defines a spherically convex inner race bearing surface. Also the outer race member defines a cavity therein with an outer race bearing surface which is concave and generally spherical therein. These two surfaces are mated to one another and have complementary profiles. The present invention provides a unique configuration for sealing of these bearing surfaces to minimize contamination thereof and to enhance retaining of lubrication therebetween. Such seals can be of any material such as rubber, however the present invention contemplates the use of plastic.
2. Description of the Prior Art
Numerous prior art patents have been granted on various configurations of spherical plain bearings with different types of seal configurations for use therewith such as shown in U.S. Pat. No. 2,631,906 patented Mar. 17, 1953 to W. H. U. Brock and assigned to Automotive Products Company Limited on a xe2x80x9cSealing Device For Fluid Pressure Apparatusxe2x80x9d; and U.S. Pat. No. 3,769,672 patented Nov. 6, 1973 to P. R. Eklund and assigned to The United States of America as represented by the Secretary of the Air Force on a xe2x80x9cMethod Of Making An Improved Teflon-Lined Spherical Bearing; and U.S. Pat. No. 3,832,022 patented Aug. 27, 1974 to H. L. Reinsma et al and assigned to Caterpillar Tractor Co. on a xe2x80x9cDual Seal Arrangement For A Spherical Jointxe2x80x9d; and U.S. Pat. No. 3,848,938 patented Nov. 19, 1974 to L. Stella et al and assigned to The Torrington Company on a xe2x80x9cBearing And Bearing Sealxe2x80x9d; and U.S. Pat. No. 3,947,075 patented Mar. 30, 1976 to H. P. Ewertz and assigned to Valley-Todeco, Inc. on a xe2x80x9cBearing Systemxe2x80x9d; and U.S. Pat. No. 4,080,013 patented Mar. 21, 1978 to H. W. Kock and assigned to Roller Bearing Company of America on a xe2x80x9cSealed Self-Aligning Spherical Bushingxe2x80x9d; and U.S. Pat. No. 4,080,015 patented Mar. 21, 1978 to D. F. Greby et al and assigned to Lear Siegler, Inc. on a xe2x80x9cBearing And Method For Manufacturing Samexe2x80x9d; and U.S. Pat. No. 4,435,023 patented Mar. 6, 1984 to T. E. Bolner and assigned to Thiokol Corporation on an xe2x80x9cInternally Actuated Spherical Bearingxe2x80x9d; and U.S. Pat. No. 4,522,411 patented Jun. 11, 1985 to T. J. Burgan and assigned to Chicago Rawhide Mfg. Co. on xe2x80x9cFluid Seals With Self-Venting Auxiliary Lipsxe2x80x9d; and U.S. Pat. No. 4,531,747 patented Jul. 30, 1985 to T. Miura and assigned to Nippon Oil Seal Industry Co., Ltd. on an xe2x80x9cExtended Wear Annular Oil Sealxe2x80x9d; and U.S. Pat. No. 4,836,694 patented Jun. 6, 1989 to P. R. Schmehr et al and assigned to SKF Gleitlager GmbH on a xe2x80x9cBearing Sealxe2x80x9d; and U.S. Pat. No. 5,002,406 patented Mar. 26, 1991 to J. R. Morton et al and assigned to Emerson Electric Co. on a xe2x80x9cSealing Structure For A Spherical Bearing Assemblyxe2x80x9d; and U.S. Pat. No. 5,125,672 patented Jun. 30, 1992 to H. Wycliffe and assigned to The BOC Group plc on xe2x80x9cShaft Sealing Arrangementsxe2x80x9d; and U.S. Pat. No. 5,385,352 patented Jan. 31, 1995 to I. Kurose and assigned to Uchiyama Manufacturing Corp. on a xe2x80x9cSealing System For Bearings, Particularly Radial-Type Bearingsxe2x80x9d; and U.S. Pat. No. 5,573,336 patented to M. E. Maroney on Nov. 12, 1996 on a xe2x80x9cSeal For A Spherical Plain Bearingxe2x80x9d; and U.S. Pat. No. 5,909,880 patented Jun. 8, 1999 to W. P. Waskiewicz and assigned to The Torrington Company on a xe2x80x9cPolymer Bearing Seal And Sealed Bearingxe2x80x9d; and U.S. Pat. No. 5,967,899 patented Oct. 19, 1999 to B. Schierling and assigned to Mannesman Sachs AG on a xe2x80x9cCentrifugal Mass Device With An Axial Slide Bearing As Sealxe2x80x9d; and U.S. Pat. No. 5,980,115 patented Nov. 9, 1999 to S. C. Hoeting and assigned to Setco Sales Co. on a xe2x80x9cBearing Seal With Uniform Fluid Purgexe2x80x9d; and U.S. Pat. No. 6,000,854 patented Dec. 14, 1999 to M. Kellstrom et al and assigned to Aktiebolaget SKF on a xe2x80x9cSealed Bearingxe2x80x9d; and U.S. Pat. No. 6,003,876 patented Dec. 21, 1999 to T. Yamagishi et al and assigned to Koyo Seikl Co., Ltd. on a xe2x80x9cSealing Member And Capped Bearingxe2x80x9d; and U.S. Pat. No. 6,024,495 patented Feb. 15, 2000 to M. Loos et al and assigned to Asea Brown Boveri AG on an xe2x80x9cAxial Sliding Bearingxe2x80x9d; and U.S. Pat. No. 6,026,917 patented Feb. 22, 2000 to A. F. Zabradnik et al and assigned to Baker Hughes Incorporated on an xe2x80x9cEarth-Boring Bit With Improved Bearing Sealxe2x80x9d; and U.S. Pat. No. 6,030,124 patented Feb. 29, 2000 to R. Moseberg et al and assigned to INA Walzlager Scvhaeffler oHG on a xe2x80x9cLinear Rolling Bearing With Longitudinal Sealing Elementsxe2x80x9d; and U.S. Pat. No. 6,036,435 patented Mar. 14, 2000 to R. A. Oklejas and assigned to Pump Engineering, Inc. on a xe2x80x9cThrust Bearingxe2x80x9d; and U.S. Pat. No. 6,042,272 patented Mar. 28, 2000 to M. Nagase and assigned to NSK Ltd. on a xe2x80x9cRolling Bearing With A Sealing Devicexe2x80x9d; and U.S. Pat. No. 6,062,734 patented May 16, 2000 to A. Bundgart and assigned to SKF Sverige AB on a xe2x80x9cBearing Sealxe2x80x9d; and U.S. Pat. No. 6,065,879 patented May 23, 2000 to N. Mitsue et al and assigned to NSK Ltd. on a xe2x80x9cRolling Bearing With Sealxe2x80x9d; and U.S. Pat. No. 6,068,407 patented May 30, 2000 to E. Kobayashi et al and assigned to Minebea Kabushiki-Kaisha on a xe2x80x9cSeal For An Anti-Friction Bearingxe2x80x9d; and U.S. Pat. No. 6,073,933 patented Jun. 13, 2000 to D. E. Johnson and assigned to Freudenberg-NOK General Partnership on a xe2x80x9cLoad Bearing Washer And Dirt Excluderxe2x80x9d; and U.S. Pat. No. 6,082,901 patented Jul. 4, 2000 to T. N. Arvidsson and assigned to Andritz Inc. on an xe2x80x9cHydraulic Axial Bearingxe2x80x9d; and U.S. Pat. No. 6,082,905 patented Jul. 4, 2000 to A. Vignotto et al and assigned to SKF Industrie S.p.A. on a xe2x80x9cSealing Assembly For A Rolling Bearingxe2x80x9d; and U.S. Pat. No. Re. 36,804 patented Aug. 1, 2000 to K. Kajhara et al and assigned to Koyo Seiko Co., Ltd. on a xe2x80x9cBearing Sealing Device And Bearing Sealing Mechanism Capable Of Preventing The Leakage Of Greasexe2x80x9d; and U.S. Pat. No. 6,102,575 patented Aug. 15, 2000 to R. Obara and assigned to Minebea Co., Ltd. on a xe2x80x9cCompound Bearing Apparatusxe2x80x9d; and U.S. Pat. No. 6,103,164 patented Aug. 15, 2000 to S. Bebjak et al and assigned to Firma Druckgusswerk Mossner GmbH on a xe2x80x9cMethod For Manufacturing A Seal In A Bearing Groove Of A Cylinder Headxe2x80x9d; and U.S. Pat. No. 6,123,338 patented Sep. 26, 2000 to L. Edelmann and assigned to SKF Linearsysteme GmbH on a xe2x80x9cRadial Seal For Ball Bearingxe2x80x9d; and U.S. Pat. No. 6,126,321 patented Oct. 3, 2000 to M. W. K. Fetty et al and assigned to Brenco Incorporated on a xe2x80x9cShaft Journal Bearing And Seal Wear Ring Assemblyxe2x80x9d; and U.S. Pat. No. 6,132,096 patented Oct. 17, 2000 to P. Damour et al and assigned to Glyco-Metal-Werke Glyco B.V. and Co. KG on a xe2x80x9cBearing Bush And Method For The Production Thereofxe2x80x9d; and U.S. Pat. No. 6,132,099 patented Oct. 17, 2000 to P. Olszewski et al and assigned to INA Walzlager Schaeffler OHG on a xe2x80x9cRadial Bearing For A Vehicle Drive Shaftxe2x80x9d.
The present invention provides a uniquely configured spherical plain bearing which utilizes a dual spread lock sealing device for preventing contamination of the bearing surface and for maintaining lubrication thereover. The plain bearing itself includes an inner race member which defines an inner race bearing surface extending externally therearound. This inner race bearing surface is preferably of a generally spherically convex shape.
An outer race member is also included which includes an outer race body which defines a bearing cavity therein which is adapted to receive the inner race member positioned therein in such a manner as to be movable to form the rotational and spherical capability of movement of the relative bearing pieces. The outer race member further includes an outer race bearing surface defined within the bearing cavity. This outer race bearing surface is generally spherically concave and is positioned in abutment with and movable with respect to the inner race bearing surface of the inner race member whenever the inner race member itself is positioned within the bearing cavity of the outer race member. This outer race body will preferably define a seal mounting groove extending therearound at a position adjacent to the outer race bearing surface to facilitate sealing of the mated concentric spherical bearing surfaces.
In the preferred configuration the seal of the present invention is capable of being positioned within the seal mounting groove in such a manner as to retain lubrication between the inner race bearing surface of the inner race member and the outer race bearing surface of the outer race member. This seal will also have the effect of minimizing the flow of contaminants therebetween.
The particular construction of the seal includes a seal base member adapted to be positioned within the seal mounting groove defined in the outer race body for retaining therewithin. The seal may also preferably include an outer lip of flexibly resilient material which is attached to the seal base member and extends outwardly therefrom toward the inner race bearing surface. This outer lip member preferably is flexibly resiliently biased into abutment with this inner race bearing surface. The outer lip is also preferably oriented at an acute angle relative to the inner race bearing surface.
An inner lip is also included in the seal means formed of flexibly resilient material which is attached to the seal base member and extends outwardly therefrom toward the inner race bearing surface and resiliently biased into contact therewith. This inner lip will preferably be oriented at an acute angle relative to the inner race bearing surface.
In the preferred configuration of the present invention the seal base member, the outer lip and the inner lip will all be configured as a single integral member formed preferably of plastic and more particularly preferably formed of white nitrile.
Furthermore the inner lip of the present invention is preferably positioned extending inwardly toward the area of abutment between the inner race bearing surface and the outer race bearing surface. Also in the preferred configuration the outer lip of the seal is positioned extending outwardly away from the area of contact between the inner race bearing surface and the outer race bearing surface in order to maintain double lubrication sealing therebetween and to enhance positioning of the seal base member into the seal mounting groove by flexibly resilient force exerted thereon through the outer and inner lips.
In another preferred configuration the outer lip and the inner lip will be oriented at approximately sixty degrees with respect to one another, one oriented toward the mated bearing surfaces and one oriented away from the bearing surfaces. Also the outer lip means will be oriented at approximately sixty degrees relative to the inner race bearing surface in one direction and the outer lip means will be oriented at approximately sixty degrees relative to the inner race bearing surface in the other direction.
To achieve effective sealing it is preferred that the seal mounting groove be positioned extending along the outer periphery of the outer race bearing surface to facilitate retaining of lubrication between the bearing surfaces and to minimize contamination thereof. To further facilitate lubrication the inner lip means may defined one or more and preferably four individual lubrication holes extending therethrough to facilitate movement of lubrication over the inner race bearing surface between the outer lip and the inner lip.
It is preferable that the seal means be formed of a material sufficiently flexibly resilient in order to allow the outer lip and the inner lip to flex outwardly with respect to one another in order to temporarily increase the angular relationship therebetween whenever force is exerted on the seal base member directed downwardly approximately perpendicular to the inner race bearing surface. In this manner insertion of the seal into the groove by compression of the overall seal and movement toward the seal mounting groove is greatly facilitated.
It is preferable that the outer lip means and the inner lip means also act for the purpose of wiping the bearing surface over which they are caused to move during the normal range of movement of the inner race member relative to the outer race member. This wiping will maintain the lubrication within the inner and outer lips and across the bearing surfaces within the inner lip such that the outer lip will be formed to include an outer pointed end oppositely located from the seal base member thereon for facilitating sealed contact and wiping of the inner race bearing surface. Similarly it is preferable that the inner lip include an inner pointed end oppositely located from the seal base member to facilitate maintaining of sealed contact and wiping of the bearing surface.
The configuration of the seal mounting groove of the present invention can be symmetrical or asymmetrical and it has been found that the present invention is workable with both configurations as long as the properly mated configuration for the seal base member of the seal is chosen for use with that particular application. That is, the seal base member must define an external groove engaging surface which has a complementary shape mated to the mounting channel section defined in the seal mounting groove into which the seal base member is adapted to be positioned.
In the preferred configuration of the present invention the inner race member will be formed as an inner ring member and the outer race member will be formed as an outer ring member. With this configuration the inner race bearing surface and the outer race bearing surface will be formed as complementary concentric spherical surfaces.
With the outer race member formed ring shaped it will preferably define a first outer race opening and a second outer race opening on opposite sides of the outer race bearing surface. Each of these openings will preferably be in fluid flow communication with respect to the bearing cavity and, as such, require the positioning of a first sealing member around the first outer race opening and a second sealing member positioned about the second outer race opening for maintaining a lubrication between the first and second outer race openings.
The seal device as disclosed in the present invention can also be usable in sealing the inner race member with respect to a movable member which may be positioned protruding therethrough. Normally with such bearings as in the present invention a movable member will extend through a channel defined in the ring-shaped inner race member. As such, this channel means will include a first inner race opening and a second inner race opening. A first channel groove will be defined in the channel means adjacent the first inner race opening. Similarly a second channel groove will be positioned in the channel means adjacent the second inner race opening. This will necessitate the inclusion of a sealing device defined herein as the first supplemental sealing device to be mounted in the first channel groove for sealing between the movable member and the inner surface of the channel of the inner race member. Similarly a second supplemental sealing device will be mounted within the second channel groove for sealing of the channel therebetween responsive to this same movable member being positioned extending therethrough.
The configuration of the first supplemental sealing device will include a first supplemental seal base member adapted to be positioned in the first channel groove defined in the channel. A first supplemental outer lip of flexibly resilient material will preferably be integrally formed with the first supplementary seal base member and will extend outwardly therefrom away from the channel. This first supplementary outer lip means will preferably be oriented at an acute angle relative to the channel. The first supplementary outer lip means will be integrally formed with the first supplementary seal base member. Furthermore the first supplementary sealing device will include a first supplementary inner lip of flexibly resilient material attached to the first supplementary seal base member and extending outwardly therefrom away from the first supplementary outer lip. The first supplementary inner lip will be oriented at an acute angle relative to the channel. This first supplementary inner lip will be integrally formed preferably with respect to the first supplemental seal base member.
A second supplementary sealing device will be similarly constructed to the first supplementary sealing device and will include a second supplementary seal base member, a second supplementary outer lip and a second supplementary inner lip and will be positioned within the second channel groove means defined in the channel for sealing of the second inner race opening extending therethrough.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which effectively prevents the movement of contaminants between the bearing surface.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which effectively minimizes the loss of lubrication from the area of contact between the mated bearing surfaces.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which can include a hole extending through the seal for lubricating of an area between the inner and outer lips of the dual sealing members.
The present invention provides a spherical plain bearing with a spread lock dual sealing means wherein an inner and outer lip are each included extending in opposite directions to facilitate flexible resilience of sealing and to enhance seal in the seal mounting groove.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which is particularly usable for spherical plain bearings including two concentric spherical bearing surfaces.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which maintains firm securement between the dual sealing lips and the bearing surfaces even after substantial wear has occurred from use.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which includes flexibly resilient lip members engaging the bearing surface for wiping and sealing thereof made from plastic or white nitrile.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which is usable with symmetrical or asymmetrical seal mounting grooves.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which allows full flushing of lubrication.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which is of minimal cost.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which requires a minimum amount of maintenance.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which can be easily installed by compressing and sliding into the seal mounting groove.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which effectively seals in both directions to prevent the escape of lubrication and prevents the inflow of contaminants.
The present invention provides a spherical plain bearing with a spread lock dual sealing means which can use the identical sealing system for sealing between a movable member penetrating through the channel in the inner ring for lubrication between this movable member and the inner ring securement surface.